installation help

[croghanite]

Anyone know the proper way to install a 6" crock through the wall using the 'wall patch method' shown here?
https://www.hearth.com/econtent/index.php/articles/passing_a_chimney

Does the entire length of the crock need to be surrounded with 12" of brick?

 

[begreen]

Not if using a prefabricated thimble. If you can post some details about your installation describing the current set up and chimney we may be able to offer some alternatives. It would be helpful to know if this is a tile lined chimney and whether it is getting a stainless liner.

 

[croghanite]

It's an 8X8 tile lined chimney with a 6" clay crock going through the wall to the chimney. The crock is surrounded by 5" of brick on all sides that's cemented together.

I see that NFPA 211 calls for a 12" layer of brick around all sides of the crock. Does it have to be a solid 12" on all sides even inside the wall?

 

[croghanite]

Its already installed and I think the easiest way to make the install safe is to build up the brick out to the 12" NFPA suggests.

I just need to know if I have to make it solid all the way through the wall. I want to make sure it's right.

I am burning with a Jotul 500

 

[begreen]

As far as I know that is the requirement. 12" of brick surrounding the tile crock to the nearest combustibles.

 

[croghanite]

That is where I become unclear on the matter. The drawing shows one layer of brick . The drawing does not show the 5" or so of space between the inner and outer wall. Do I have to fill the inside of the wall with the 12" layer of brick around the crock? The way I see it, you need the 12" of brick surrounding the crock at the wall penetrations. That is the interior and exterior wall. Any combustables inbetween the wall must be 18" away from the crock.

Which is it?

 

[begreen]

Sounds like this is a non-standard wall of unusual depth. Is that correct? Is it a staggered stud wall?

Essentially I think you have the right idea, but without seeing the actual issue in a picture or drawing, I'm not positive. Craig's article does show a wall gap which I've taken the liberty of posting here with a question for the 5" gap. If this is incorrect, can you post a side view drawing of the set up. I'd also pm Craig with a link to this thread and ask him to take a look after posting. Best to be sure there are no bad instructions here.

 

[croghanite]

Thank you for your help sir. I hope to have some time to draw a picture and post it tomorrow.

I believe the gap that is shown in the picture where you added the 5" arrow is the minimum 2" gap that NFPA recommends the outer chimney wall to be from the outside of the building wall.
See the NFPA pic in this thread:
https://www.hearth.com/econtent/index.php/forums/viewthread/48872/#539220

See how the picture shows one layer of brick for the outer building wall as if the outer wall of a home is that thick????? That part of the picture is what is confusing to me. It makes me think that the entire run of the clay sleeve should be surrounded with 12" of brick cemented into place.

I just want to make sure. Thanks again for the help.

 

[croghanite]

Sounds like this is a non-standard wall of unusual depth. Is that correct? Is it a staggered stud wall?

Essentially I think you have the right idea, but without seeing the actual issue in a picture or drawing, I'm not positive. Craig's article does show a wall gap which I've taken the liberty of posting here with a question for the 5" gap. If this is incorrect, can you post a side view drawing of the set up. I'd also pm Craig with a link to this thread and ask him to take a look after posting. Best to be sure there are no bad instructions here.

The picture shown is my setup except the brick wall shown on your pic would be a 10" thick studded wall at my house. I'm going to go ahead and just brick the whole thing up all the way through but I would still like to know what NFPA recommends.

I took the time to draw up a nice pic on autocad but can't figure out how to get it sized down to post it :red:

Thanks for the help

 

[webbie]

I agree that it should be bricked the whole way through. There is no way that a regular crock should be in "free air" as it is not designed to do that. A crock must be fully surrounded by masonry one way or the other. NFPA seems to skip some details here and there....the 2" thing (from the wall) also confuses the matter.
What makes it even harder is what to do with the siding on many houses, which is combustible!

 

[croghanite]

Case closed

Thanks for the help folks!

 

[Fsappo]

How come in 25+ years I am only now hearing the term crock? Is that another word for clay tile, or clay thimble?

 

[croghanite]

How come in 25+ years I am only now hearing the term crock? Is that another word for clay tile, or clay thimble?

Yes. Synonymous with a clay thimble.

 

[begreen]

I'm curious about how the wall ended up 10" thick?

No idea how many bricks it will take to fill up that 32" sq hole, 10" deep, but I suspect it will be very heavy. I would build a header under them instead of a simple sill and add side cripples and a stout center brace in the center to hold the weight without sagging over time.

 

[croghanite]

I may bust the wall open tonight or maybe tommorow. I opened up a different wall in this side of the house to find the previous owner used LOGS to build this part of the house. I reckon that there is gonna be a big 'ol log directly in my way.

Thanks for the idea, I didn't think about the weight.....